Recent History of Customer Service:
Call centers handle customers virtually --> call centers employed IVR to reduce the number of agent assisted calls to reduce high call center costs --> Customer self-service was added to company websites to reduce IVR calls to reduce user experience complaints that resulted in the IVR calls rolling to the call center
The first user interface I worked on in my user experience career was an application for call center representatives. I have a special fondness for the customer service profession, since it was there that I first researched, designed and tested an application with end users who were generous with their time and patient with my questions as I sought to understand how to tune the application to meet their needs.
Now customer self service is moving to the mobile web on smart phones. Astonishingly, more people will have smartphone web access than those who have traditional web access by 2012 or so. While companies needed to retain IVR because they couldn't count on their customer to have web access, now your customer will expect you to get where they are. Companies will need to get their services mobilized or lose their customer to the company who is. People won't blunder along in an IVR system and they won't wait in the Queue at your call center. They want to do business with you company and they want to do it while waiting for their Tall Americano with room for cream.